diff --git a/src/lib/bitstream.c b/src/lib/bitstream.c
index c49c4ff..5bd235e 100644
--- a/src/lib/bitstream.c
+++ b/src/lib/bitstream.c
@@ -73,6 +73,33 @@ void shine_putbits(bitstream_t *bs, unsigned int val, unsigned int N)
 	}
 }
 
+/*
+ * shine_flush_end_of_frame:
+ * -------------------------
+ * Flush remaining bits of the frame to the bitstream. Must be called only at end of
+ * frame, because only then is the cache guaranteed to be filled to a byte boundary.
+ */
+void shine_flush_end_of_frame(bitstream_t *bs)
+{
+	int bits_to_flush;
+	int cache_bytes;
+
+	if (bs->cache_bits < 32) {
+		bits_to_flush = 32 - bs->cache_bits;
+
+		/* fill the remaining cache bits with zeros (they will be ignored). */
+		shine_putbits(bs, 0, bs->cache_bits);
+
+		/* correct output position because a full 4 bytes may not have been written */
+		cache_bytes = bits_to_flush / 8;
+		bs->data_position += cache_bytes - 4;
+
+		/* clear the cache for the next frame */
+		bs->cache_bits = 32;
+		bs->cache = 0;
+	}
+}
+
 int shine_get_bits_count(bitstream_t *bs)
 {
 	return bs->data_position * 8 + 32 - bs->cache_bits;
diff --git a/src/lib/bitstream.h b/src/lib/bitstream.h
index d910ef9..6b6645a 100644
--- a/src/lib/bitstream.h
+++ b/src/lib/bitstream.h
@@ -23,6 +23,7 @@ typedef struct  bit_stream_struc {
 void shine_open_bit_stream(bitstream_t *bs,const int size);
 void shine_close_bit_stream(bitstream_t *bs);
 void shine_putbits(bitstream_t *bs,unsigned int val, unsigned int N);
+void shine_flush_end_of_frame(bitstream_t *bs);
 int  shine_get_bits_count(bitstream_t *bs);
 
 #endif
diff --git a/src/lib/layer3.c b/src/lib/layer3.c
index 0b574ad..de586a6 100644
--- a/src/lib/layer3.c
+++ b/src/lib/layer3.c
@@ -165,6 +165,9 @@ static unsigned char *shine_encode_buffer_internal(shine_global_config *config,
   /* write the frame to the bitstream */
   shine_format_bitstream(config);
 
+  /* flush the cache bits to write a full frame */
+  shine_flush_end_of_frame(&config->bs);
+
   /* Return data. */
   *written = config->bs.data_position;
   config->bs.data_position = 0;
@@ -191,6 +194,8 @@ unsigned char *shine_encode_buffer_interleaved(shine_global_config *config, int1
 }
 
 unsigned char *shine_flush(shine_global_config *config, int *written) {
+  shine_flush_end_of_frame(&config->bs);
+
   *written = config->bs.data_position;
   config->bs.data_position = 0;